1. Technical Field of the Invention
This invention relates to radio teleconmunications networks and, more particularly, to a system and method of implementing an improved Calling Line Identification (CLI) feature in a radio telecommunications network.
2. Description of Related Art
Calling Line Identification (CLI) is an existing telephone feature which facilitates the display of a calling party's directory number on a called party's terminal display. In the Public Switched Telephone Network (PSTN), when a call is terminated to a called party, the calling party's directory number is sent via line signaling to the called party's terminal. The called party's terminal is equipped with a CLI device which records and displays information regarding the calling party and the calling directory number.
The CLI feature has also been adapted for use in radio telecoimmunications networks. Much like the PSTN version of the feature, in a radio telecommunications network, the calling party's directory number is sent to the called party's mobile terminal during call setup. More particularly, the calling party's directory number is sent to the called party's mobile terminal after a voice channel (or digital traffic channel) has been allocated to the terminal.
The existing CLI feature has disadvantages, however. There are circumstances in radio telecommunications networks that cause the existing feature to fail to record calling party information. For example, mobile terminals may often be unreachable because they are turned off, or the radio resources of the network are congested. In these situations, the CLI feature is unable to display or record the directory numbers of parties that attempted to call during the period that the mobile terminal was turned off or congestion prevented the allocation of a voice channel to the mobile terminal.
Although there are no known prior art teachings of a solution to the aforementioned deficiency and shortcoming such as that disclosed herein, several known references discuss subject matter that bears some relation to matters discussed herein. UK Patent Application GB 2,287,856 discloses a method of relaying calling party identification information to a remote receiver which may be a pager or another telephone. Thus, GB 2,287,856 does not teach or suggest a system or method of storing CLI information while a mobile terminal is inactive or radio channels are congested, and forwarding the stored CLI information to the mobile terminal upon notification that the mobile terminal has been reactivated or at a later time when the congestion has cleared.
U.S. Pat. No. 4,914,689 to Quade et al. (Quade) discloses a reverse number identification system that allows a called subscriber to identify the directory number of the calling party. The Quade reverse number identification system is designed for wireline telephone systems and does not teach or suggest a system or method of storing CLI information while a mobile terminal is inactive or radio channels are congested, and forwarding the stored CLI information to the mobile terminal upon notification that the mobile terminal has been reactivated or at a later time when the congestion has cleared.
U.S. Pat. No. 5,398,279 to Frain (Frain) and European Patent Application EP 0 498 997 A2 each disclose a portable cellular telephone capable of recognizing a CLI signal. The telephone includes a memory for storing telephone numbers and a counter for storing the respective number of calls received from telephone numbers stored in the memory. However, these references do not teach or suggest a system or method of storing CLI information while a mobile terminal is inactive or radio channels are congested, and forwarding the stored CLI information to the mobile terminal upon notification that the mobile terminal has been reactivated or at a later time when the congestion has cleared.
U.S. Pat. No. 5,283,818 to Klausner et al. (Klausner) discloses a telephone answering device (TAD) which includes a means for intelligently organizing voice messages, personal IDs, home telephone numbers, and information stored in the memory of the TAD. Klausner, however, does not teach or suggest a system or method of storing CLI information while a mobile terminal is inactive or radio channels are congested, and forwarding the stored CLI information to the mobile terminal upon notification that the mobile terminal has been reactivated or at a later time when the congestion has cleared.
European Patent Application EP 0 715 442 A2 discloses a method and apparatus for providing personal calling identification at remote locations. A caller from a remote telephone station may enter an alternate directory number as the number to be utilized as the calling number. However, this reference does not teach or suggest a system or method of storing CLI information while a mobile terminal is inactive or radio channels are congested, and forwarding the stored CLI information to the mobile terminal upon notification that the mobile terminal has been reactivated or at a later time when the congestion has cleared.
PCT Patent Application WO 96/06508 discloses a method of identifying a short message originator category in a digital mobile phone network. Thus, this reference discloses a type of calling line identification for short message service (SMS) messages. However, the reference does not teach or suggest a system or method of storing CLI information while a mobile terminal is inactive or radio channels are congested, and forwarding the stored CLI information to the mobile terminal upon notification that the mobile terminal has been reactivated or at a later time when the congestion has cleared.
Review of each of the foregoing references reveals no disclosure or suggestion of a system or method such as that described and claimed herein.
In order to overcome the disadvantage of existing solutions, it would be advantageous to have a system and method of storing CLI information while a mobile terminal is inactive or radio channels are congested, and forwarding the stored CLI information to the mobile terminal upon notification that the mobile terminal has been reactivated or at a later time when the congestion has cleared. The present invention provides such a system and method.